The Oil Drum

One big issue your missing is that Shell has revised its reserve estimates downward by over 50% in multiple revisions.

I can't imagine that Shell's reporting behavior and metrics differed that significantly from the rest of the industry. Given that employee's in a given field especially in the higher ranks often work for several of the large companies in a area. The chances that Shell approach to determining reserves was that badly off of industry standard is slim to none.

Next and more directly how much of the current reserves are true new discoveries ?

We discovered close to a trillion barrels of oil by 1980 and mega fields made up a fair amount of these discoveries. I question that you can discover 800GB of oil with only one giant field being discovered ? No more super giants in all those discoveries and in fact no pretty much no really large fields discovered since the 1980's ?

I think you will find the majority of these 800GB consist of backdated discovery yet even with one of the last major oil fields discovered Purdhoe Bay we had a original estimate of 10GB and a final production of probably 13GB. With the last 3GB coming out at a greatly reduced production rate.

So for now at least to be conservative we should discount 400GB of the 800GB until we have better transparency. Shell shows we cannot take these numbers on faith.

This leaves 400GB. And new we have to question how fast we can extract this 400GB how much of that is going to be extracted close to our present rate ?

Again to be conservative we say well maybe 200GB before we see a significant decline in extraction rates.

Well guess what we extract 30GB or so a year so at best 10 years before we see serious problems.

And now your at the level I'm at is it 200 or close to 100. I think its somewhere in this range. The reason I lean toward closer to 100GB is simple because Hubbert came up with a global estimate of 1250GB and he was right in his first prediction. When he did his global analysis because of the political economic climate he simply did not have access to the quality of data that he had to make his original US prediction. If anything he probably erred on the high side.

http://www.touchbriefings.com/pdf/2590/Ferro.pdf

This indicates we are at least 80% depleted based on water cut right now.

Given all this yes we may still have a significant amount of oil to extract but the chances we can extract that oil at anything close to the 80mbd+ that we do now are in my opinion slim to none. Can we do it at 40mbpd sure but that does not support our society.

So in closing using oil as a cheap energy source for powering our society is probably in its last few years.